1. Field of the Invention
The present invention relates generally to charged beam apparatus and methods, such as but not limited to electron beam apparatus and methods. More particularly, the present invention relates to charged beam aerial dimensional mapping within charged beam apparatus and methods.
2. Description of the Related Art
Within the microelectronic fabrication art, accurate measurement of a dimension of a given feature within a microelectronic structure is often critical for process control and yield learning. Commonly, the dimension of such a feature may be measured using an electron microscopy apparatus and method. Electron microscopy apparatus and methods use accelerated electrons that are focused into an electron beam that is used as a measurement probe with respect to a microelectronic feature located within or upon a microelectronic substrate. Within electron microscopy apparatus and methods, such an electron beam is often scanned across a particular feature within a microelectronic substrate. As a result of the interaction of electrons within the electron beam with a material from which is comprised the particular feature, a dimension of the particular feature may often be readily determined.
While electron microscopy apparatus and methods are common in the microelectronic fabrication art, electron microscopy apparatus and methods are nonetheless not entirely without problems. In particular, since electron microscopy apparatus and methods are predicated upon an interaction of an electron beam with a material from which is comprised a particular feature within a microelectronic structure, aerial dimensions of a particular electron beam within a particular electron microscopy apparatus and method may often be of particular importance in assuring that the dimension of the particular feature is accurately determined.
As is common in the microelectronic fabrication art, microelectronic feature dimensions within microelectronic structures are certain to continue to decrease as microelectronic structure and microelectronic device fabrication technology advances. Thus, desirable are charged beam apparatus and methods, such as in particular electron microscopy apparatus and methods, that provide for enhanced microelectronic feature dimension measurement precision and measurement accuracy as microelectronic feature dimensions decrease.